1. Field of the Invention
The present invention relates to a photographic lens incorporated in an electronic still camera or the like and, in particular, to a compact photographic lens for electronic still camera having a very small total length.
2. Description of the Prior Art
Recently, as personal computers have come into wider use in households and the like, prevailing are electronic still cameras by which image data such as photographed landscapes and portraits can be fed into personal computers.
In order to be incorporated in such an electronic still camera, it is necessary for a photographic lens to be able to attain a very short total lens system length, have a sufficient angle of view, minimize distortion, and so forth. In particular, it is necessary to place a lens system, low-pass filter, and CCD within the thickness of the electronic still camera, and the lens system is required to have a total length not greater than 20 mm, for example. Accordingly, in terms of lens design, the number of lenses is restricted to several sheets, for example.
When a wide angle of view is to be obtained by a small number of lens sheets as mentioned above, distortion may increase, thus making it difficult to attain a practically satisfactory image quality.